Electromagnet assembly

Abstract

An electromagnet assembly has an inner magnet, an outer magnet, arranged around the inner magnet with an annular region extending between the inner magnet and the outer magnet, and a number of support elements extending through the annular region and dividing the annular region into a number of annular segments. The support elements are distributed in the annular region so as to form a small annular segment and a large annular segment.

The invention claimed is: 
     
       1. An electromagnet assembly for generating a strong magnetic field under superconducting conditions, comprising:
 an inner magnet; 
 an outer magnet around the inner magnet, with an annular region extending between the inner magnet and the outer magnet; 
 a plurality of support elements extending through the annular region and dividing the annular region into a plurality of annular segments; and 
 said support elements being distributed in the annular region so as to form a first annular segment and a second annular segment, with the first annular segment being smaller than the second annular segment, 
 wherein the outer magnet comprises:
 a first coil; 
 a second coil spaced apart from the first coil; 
 the first coil defining a first annular region; 
 the second coil defining a second annular region that extends between the inner magnet and the second coil; and 
 a plurality of support elements through the second annular region. 
 
 
     
     
       2. The electromagnet assembly according to  claim 1 , wherein the second annular segment is an integer multiple of the first annular segment. 
     
     
       3. The electromagnet assembly according to  claim 1 , wherein each annular segment is an integer multiple or an integer factor of another annular segment. 
     
     
       4. The electromagnet assembly according to  claim 1 , wherein:
 the outer magnet comprises a plurality of outer support points; 
 the inner magnet comprises a plurality of inner support points; and 
 each of the support elements extends between an outer support point and an inner support point. 
 
     
     
       5. The electromagnet assembly according to  claim 4 , wherein:
 each pair of adjacent inner support points spans a distance; and 
 each distance spanned by a first pair of adjacent inner support points is an integer multiple or an integer factor of a distance spanned by a second pair of adjacent inner support points. 
 
     
     
       6. The electromagnet assembly according to  claim 4 , wherein:
 each pair of adjacent outer support points spans a distance; and 
 each distance spanned by a first pair of adjacent outer support points is an integer multiple or an integer factor of a distance spanned by a second pair of adjacent outer support points. 
 
     
     
       7. The electromagnet assembly according to  claim 1 , wherein the plurality of support elements comprises at least three support elements. 
     
     
       8. The electromagnet assembly according to  claim 1 , wherein:
 a first support element is located in a first half of the annular region; and 
 a second support element and a third support element are located in a second half of the annular region. 
 
     
     
       9. The electromagnet assembly according to  claim 1 , wherein the support elements are coplanar. 
     
     
       10. A medical imaging apparatus comprising:
 a medical image data acquisition scanner; 
 an electromagnetic assembly in said scanner that generates a strong magnetic field under superconducting conditions; and 
 said electromagnetic assembly comprising an inner magnet, an outer magnet around the inner magnet, with an annular region extending between the inner magnet and the outer magnet, a plurality of support elements extending through the annular region and dividing the annular region into a plurality of annular segments, and said support elements being distributed in the annular region so as to form a first annular segment and a second annular segment, with the first annular segment being smaller than the second annular segment, 
 wherein the outer magnet comprises:
 a first coil; 
 a second coil spaced apart from the first coil; 
 the first coil defining a first annular region; 
 the second coil defining a second annular region that extends between the inner magnet and the second coil; and 
 a plurality of support elements extending through the second annular region. 
 
 
     
     
       11. The medical imaging apparatus according to  claim 10 , wherein the electromagnet assembly provides greater support to the outer magnet along a vertical direction of the medical imaging scanner than along a horizontal direction of the medical imaging scanner. 
     
     
       12. The medical imaging apparatus according to  claim 10 , wherein the electromagnet assembly has a larger number of support elements on a first side of the medical imaging scanner than on a second side of the medical imaging scanner.